Concordance of KRAS/BRAF Mutation Status in Metastatic Colorectal Cancer before and after Anti-EGFR Therapy
Figure 2
Morphological changes and results of KRAS mutation analyses in case #43 of a heterogeneously differentiated CRC with mosaicism for KRAS mutation G12D. In Figure 2(a) moderately (right half) and undifferentiated (left half) tumor areas reveal positive detection of KRAS mutation G12V (inset). In contrast, only in soft tissue (b) and peritoneal (c) metastases harbouring exclusively undifferentiated tumor infiltrates an identical KRAS mutation was detectable ((b) and (c) insets), whereas in lymph node (e) and liver (f) metastases with moderately differentiated tumor infiltrates only, no KRAS mutation was found ((e) and (f) insets). After microdissection of undifferentiated (d) and moderately differentiated (g) areas from primary CRC the KRAS mutation G12V was only detectable in the undifferentiated fraction ((d), inset). Images were produced with a B 50 microscope (Olympus, Hamburg, Germany) and a DP50 digital camera with DP-Soft 5.0 software (Olympus, Hamburg, Germany).
